Merge pull request #3 from juanramirez/master

Fixed null pointer error and improve debian packaging.
Merge pull request #4 from juanramirez/master

Fixed path of shell interpreter.
Add target clean to remove jar files, fix target distclean and add the directory java/build to gitignore
Merge pull request #5 from rafatower/master

Fix some small things in Makefile and .gitignore
Merged with tuenti/master.